Human body has over 1000 types of neurons which aid the body to communicate with the brain. These are very minute and they can only be seen through a microscope. They have a very unique structure and they have an ability to transmit electrical pulses along with them. They help the body to identify any form of stimuli and take an appropriate action. Below is a structure of a neuron.
Human body has three major types of neurons. These include the sensory neurons, interneurons and motor neurons.
The sensory neurons
These types of neurons links the external stimuli with the interneurons. They have receptors which detect external stimuli, be it touch, sound taste, vision or odor and converts it into electrical signals which are later transmitted to the brain.
These types of sensory neurons are found in the dorsal root ganglia. They are identified with the axioms receptors which normally extend in either directions of the sensory neurons.
One end is normally located in the receptor cells to detect any form of stimuli while the other is normally located in the spinal cord where it links with the interneuron.
This provide an efficient signal transmission to the brain for an appropriate cause of action to be taken.
Below is a diagram of a sensory neuron.
These types of neurons are mainly located in the spinal cord and the brain. They are normally stimulated by signals from an eternal stimuli through the sensory neurons or from other interneurons. At times, interneurons can be stimulated by both the interneurons and sensory at the same time. The diagram below shows examples of interneurons.
Just like the sensory neurons, these types of neurons exist in a large number in both the spinal cord and the brain. Their number is approximately over ten billion.
Interneurons serve the following purpose in the human body:
– They act as a path through which the signal is received and transmitted to the central nervous system besides aiding in transmitting of commands from the central nervous system.
– They have the ability to integrate both the incoming and outgoing signal and protect the neurons functions at the same time.
The motor neuron
This is also another important type of neuron in the body. They are known to in the transmission of signals to either the muscles or the glands from the central nervous system. They are specifically adapted to execute responses.
The motor neurons are normally stimulated by the interneurons however, at times, they can also be stimulated by the sensory neurons.
The diagram below shows an example of a motor neuron
Different types of neurons can also be classified on the basis of their structure. For instance, neurons can be classified as:
– Unipolar neurons; these types of neurons are characterized by a single fiber. An example of a unipolar neuron is the sensory neuron.
– Multipolar neuron; examples of these neurons are interneurons and motor neurons. These types of neurons are characterized by multiple cell processes
– Bipolar neurons; examples of these types of neurons are those found on the eye’s retina. They are mostly spindle shaped with axon on one end and dendrite on the other.
All these neurons depend on one another for proper communication and therefore failure of any of them my result to improper coordination.